1. Internet content moderation

Think of the most disgusting things you've stumbled across online. Now imagine viewing the stuff that nightmares are made of - hate crimes, torture, child abuse - in living colour, from nine to five every day. That's the work of internet content moderators, who get paid to filter out that kind of material so you don't have to see it pop up on a social network or photo-sharing site. Demand for the work is growing, especially as more web-based services enable users to post pictures instantly from their mobile devices.

"Obviously it's not the job for everyone," says Stacey Springer, vice president of operations at Caleris. The US company's 55 employees scan up to seven million images every day for some 80 different clients.

"Some people might take it personally if they have a child and see images of children that might be sensitive to them, or if they see animal cruelty."

Caleris content reviewers receive free counselling as well as benefits including health insurance, but for some the psychological scars don't heal easily.

2. Electronics assembly

Safety nets around the dorms of an electronics factory in Shenzen, China, are a grim reminder that ten employees have jumped to their death there since January. A 25-year-old employee who later committed suicide reportedly had been beaten at the Hon Hai plant after losing a prototype iPhone 4 last year.

Recall the frenzy, hoopla, and queues at the launch of Apple's latest smartphone, and you can imagine the deadline pressure for the people assembling it. Foxconn, which makes iPhones, iPads, and other electronics for Apple, Dell, and HP, has been accused of fostering 'sweatshop' conditions. However complex the chain of events leading to suicide may be, human-rights groups have criticised Foxconn and other manufacturers for creating an unbearable, pressure-cooker environment for workers, mostly young migrants from rural areas.

In light of the suicides, the company has raised wages, promised psychological testing for employees, and tried to boost morale with rallies. Foxconn plans to increase its workforce of more than 900,000 to 1.3 million in the next year.

Psychological pressure isn't the only rough condition reported in electronics factories, though. Labour and human-rights organisations also charge that workers testing microchips and assembling LCDs for Samsung were exposed to radiation that caused cancer.

You may not think working in technology could be dangerous, but you'd be wrong. Some professions are particularly perilous, and could even involve you risking your own life. We've rounded up a list of the seven most dangerous jobs in technology.

3. Fixing undersea internet cables

Cables that span the oceans keep people connected online across continents. Contrary to popular belief, it's hard connections such as these - not satellites in space - that provide more than 99 percent of the world's internet connectivity. Someone has to lay and fix those cables when an undersea earthquake or errant anchor cuts off the data flow.

The crew of the vessel 'Pacific Guardian' recovers a cable for repair to restore telecom links across the Atlantic. Credit: Global Marine Systems

About 70 vessels around the world are tasked with fibre-optics installation and repairs. Some are on call around the clock. Each has a crew of about 50 people, including cable-installation engineers and controllers of remote-operated vehicles, who spend weeks or months at sea.

Robots rather than human divers lay and bury cables in the seabed as deep as 16,000 feet below the water's surface, but it takes the human hands on deck to haul in, repair, and drop heavy cables. Though they wear rubber gloves, in a worst-case scenario a cable operating with 10,000 volts could become energised. And looking straight into the lasers of a sliced cable can burn out your retinas in a matter of seconds.

As with fishing - perhaps the deadliest profession - this job carries the risk of encountering 'acts of God' on the sea. Members of the crew are also prone to slips, trips, and falls on wet decks.

Elaborate layers of safeguards on the vessels reflect the dangerous nature of the work, says John Davies, managing director for Global Marine Systems, the largest company that handles submarine internet cables.

4. Communications-tower climbing

Close to 11,000 people install and fix the communications towers that keep mobile calls connected in the US. In 2006, 18 of them died on the job. The head of the Occupational Safety and Health Administration in 2008 called mobile-phone-tower climbing the most dangerous work in America.

"Clearly it was the most dangerous job if you looked at a niche industry," says Craig Lekutis, president of the news portal WirelessEstimator.com.

Communications towers can reach 2,000 feet high. The industry has made improvements, but any work at extreme heights involves the risk of a fall. Fatalities tend to happen when workers don't use the right safety gear, or when they disconnect just for a moment. When a person is positioned 30 to 2000 feet in the air, such shortcuts can make routine tasks - such as testing an antenna - deadly. Accidents can happen even when the employee takes precautions; a tower can weaken at its base and fall, for instance, or a lanyard can break from a safety harness.

Amid a construction boom to make way for 3G and 4G wireless networks, Lekutis estimates, a quarter of a million communications towers - and rising - could be in need of installation or repair, in the US alone.

You may not think working in technology could be dangerous, but you'd be wrong. Some professions are particularly perilous, and could even involve you risking your own life. We've rounded up a list of the seven most dangerous jobs in technology.

5. Unregulated e-waste recycling

When you send an old computer or CRT monitor off for recycling, chances are it will end up on a tip halfway around the world rather than being dismantled safely nearby. Used hardware from the industrialised world often travels thousands of miles to developing parts of Asia and Africa.

People hoping to earn a wage collect machines and smash them with crude tools to strip gold, silver, and other precious metals out of circuit boards. They may come into dangerous contact with lead, cadmium, beryllium, mercury, and brominated flame retardants. Some are exposed to more chemical harm by soaking circuit boards in acid, or burning PVC cabling to retrieve copper.

Workers at this e-waste processing center in Bangalore, India, have more protection than others. Credit: Silicon Valley Toxics Coalition

"That has to be one of the most treacherous jobs around, especially in light of the products being handled," says Sheila Davis, head of the non-profit Silicon Valley Toxics Coalition.

"We see children in India smashing these monitors with sandals and no protective gear, and exposure to lead can cause significant neurological diseases and learning disabilities."

In addition, inmates in some US prisons are exposed to the same toxic substances in e-waste recycling operations.

The US government doesn't closely track what happens to spent electronics. To prevent your used gear from being recycled under poor working conditions, resell or donate the equipment to someone who will keep it in use.

6. Mining 'conflict minerals'

The eastern Congo is rich in the key ingredients that keep electronics ticking. The area holds tantalum for use in capacitors, tin for circuit-board solder, tungsten to make cell phones vibrate, and gold for connecting components. Despite such natural wealth, tens of thousands (or, by some estimates, hundreds of thousands) of people work in appalling conditions to extract those materials.

"Potentially each and every one of our cell phones, laptop computers, and PCs contains some of these conflict minerals," says Sasha Lezhnev, a researcher for human-rights group Global Witness.

"It's analogous to blood diamonds. You get a bunch of people digging in river streams by hand. Some are carving out a mountain literally. When I went out to the mines, I met many children as young as 11 years old. There were military commanders with AK-47s easily extracting money from everyone who mines."

Armed Congolese groups earn about $180m each year in this trade, while the majority of the people live in poverty. Smugglers take $1bn in materials out of the country every year, according to the Congolese government.

No tech company has been able to audit and certify that all of its products are 'conflict-free', but some - including Intel and Motorola - are taking steps in that direction.

You may not think working in technology could be dangerous, but you'd be wrong. Some professions are particularly perilous, and could even involve you risking your own life. We've rounded up a list of the seven most dangerous jobs in technology.

7. Infrastructure work in war zones

A dangerous job in peacetime is one thing, but try focusing on a task when you're the potential target for a sniper or a bomb. Whether building communications infrastructure for civilians or military operations, military personnel and private contractors in the conflict zones of Iraq and Afghanistan risk their lives on a regular basis.

It's unclear exactly how many people doing IT-related work have lost their lives among the 4735 Coalition military deaths in Iraq since 2003, and the 2026 dead in Operation Enduring Freedom since 2001 so far, as counted on the independent iCasualties website.

According to a count conducted in September 2009, at least three telecommunications engineers are among the 533 foreign private contractors who have died in Iraq since the beginning of the conflict there. Two telecom engineers are among the 146 private foreign contractors who have perished in Afghanistan.